The present invention relates generally to a valve by which a representative sample can be transferred from a high temperature, erosive critical solvent deashing unit feed stream, to the analytical stages of a feed quality monitor in a predictable amount at controlled time intervals.
Conventional ball valves are unsatisfactory for use in sampling erosive, process streams ash-containing such as those found in coal conversion processes. Ball-type valves are not well suited for use in these process streams because buildup of erosive particles in the internal body cavities of the valve during rotation tends to cause abnormal wear. This solids buildup within the valve brings about scoring and erosion of the ball during operation, thereby producing a faulty operation and eventual failure of the valve. Costly and time consuming replacement of the valve after such failure has an adverse affect on system reliability during unattended operation and the potential for process control of the critical solvent deashing feed quality monitoring system.
It is, accordingly, a general object of the invention to develop a more durable and reliable valve to provide on-line continuous, unattended sampling of the critical solvent deashing feed stream.